cdt/cdt_6_0_x/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/ui/editors/AbstractDebugTextHover.java
/*******************************************************************************
* Copyright (c) 2000, 2007 QNX Software Systems and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* QNX Software Systems - Initial API and implementation
* Nokia - Refactored from DebugTextHover to remove CDI dependency
*
*******************************************************************************/
package org.eclipse.cdt.debug.ui.editors;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.cdt.debug.internal.ui.CDebugUIUtils;
import org.eclipse.cdt.debug.ui.CDebugUIPlugin;
import org.eclipse.cdt.ui.text.c.hover.ICEditorTextHover;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.ui.IDebugUIConstants;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextHoverExtension;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IPartListener;
import org.eclipse.ui.ISelectionListener;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchPart;
/* The class LanguageOperators protects some language specific
* operator information used by the DebugTextHover class.
*/
class LanguageOperators {
public String getAssignmentOperator() {
return "="; //$NON-NLS-1$
}
public String getGreaterThanEqualToOperator() {
return ">="; //$NON-NLS-1$
}
public String getEqualToOperator() {
return "=="; //$NON-NLS-1$
}
public String getNotEqualToOperator() {
return "!="; //$NON-NLS-1$
}
public String getLessThenEqualToOperator() {
return "<="; //$NON-NLS-1$
}
public String getValueChangeOperatorsRegex() {
return "(\\+\\+)|(\\-\\-)|(\\+\\=)|" //$NON-NLS-1$
+ "(\\-\\=)|(\\*\\=)|(/\\=)|(\\&\\=)" //$NON-NLS-1$
+ "(\\%\\=)|(\\^\\=)|(\\|\\=)|(\\<\\<\\=)|(\\>\\>\\=)"; //$NON-NLS-1$
}
public String getEqualToOperatorsRegex() {
return "\\=\\=|\\<\\=|\\>\\=|!\\="; //$NON-NLS-1$
}
public String getIdentifierRegex() {
return "[_A-Za-z][_A-Za-z0-9]*"; //$NON-NLS-1$
}
}
/**
* The text hovering support for C/C++ debugger.
*
* @since 6.1
*/
public abstract class AbstractDebugTextHover implements ICEditorTextHover, ITextHoverExtension,
ISelectionListener, IPartListener {
static final private int MAX_HOVER_INFO_SIZE = 100;
private ISelection fSelection = null;
private IEditorPart fEditor;
protected abstract boolean canEvaluate();
protected abstract String evaluateExpression(String expression);
public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
if (canEvaluate()) {
try {
IDocument document = textViewer.getDocument();
if (document == null)
return null;
String expression = document.get(hoverRegion.getOffset(),
hoverRegion.getLength());
if (expression == null)
return null;
expression = expression.trim();
if (expression.length() == 0)
return null;
LanguageOperators operatorsObj = new LanguageOperators();
Pattern pattern = Pattern.compile(operatorsObj
.getValueChangeOperatorsRegex());
Matcher matcher = pattern.matcher(expression);
boolean match_found = matcher.find();
// Get matching string
// If the expression has some operators which can change the
// value of a variable, that expresssion should not be
// evaluated.
if (match_found) {
return null;
}
pattern = Pattern.compile(operatorsObj
.getEqualToOperatorsRegex());
String[] tokens = pattern.split(expression);
for (int i = 0; i < tokens.length; i++) {
//If the expression contains assignment operator that
// can change the value of a variable, the expression
// should not be evaluated.
if (tokens[i].indexOf(operatorsObj
.getAssignmentOperator()) != -1)
return null;
}
//Supressing function calls from evaluation.
String functionCallRegex = operatorsObj.getIdentifierRegex() + "\\s*\\("; //$NON-NLS-1$
pattern = Pattern.compile(functionCallRegex);
matcher = pattern.matcher(expression);
match_found = matcher.find();
if (match_found) {
return null;
}
StringBuffer buffer = new StringBuffer();
String result = evaluateExpression(expression);
if (result == null)
return null;
try {
appendVariable(buffer, makeHTMLSafe(expression), makeHTMLSafe(result.trim()));
} catch (DebugException x) {
CDebugUIPlugin.log(x);
}
if (buffer.length() > 0) {
return buffer.toString();
}
} catch (BadLocationException x) {
CDebugUIPlugin.log(x);
}
}
return null;
}
public IRegion getHoverRegion(ITextViewer viewer, int offset) {
/*
* Point selectedRange = viewer.getSelectedRange(); if ( selectedRange.x >= 0 && selectedRange.y > 0 && offset >= selectedRange.x && offset <=
* selectedRange.x + selectedRange.y ) return new Region( selectedRange.x, selectedRange.y );
*/
if (viewer != null)
return CDebugUIUtils.findWord(viewer.getDocument(), offset);
return null;
}
/**
* Append HTML for the given variable to the given buffer
*/
private static void appendVariable(StringBuffer buffer, String expression, String value) throws DebugException {
if (value.length() > MAX_HOVER_INFO_SIZE)
value = value.substring(0, MAX_HOVER_INFO_SIZE) + " ..."; //$NON-NLS-1$
buffer.append("<p>"); //$NON-NLS-1$
buffer.append("<pre>").append(expression).append("</pre>"); //$NON-NLS-1$ //$NON-NLS-2$
buffer.append(" = "); //$NON-NLS-1$
buffer.append("<b><pre>").append(value).append("</pre></b>"); //$NON-NLS-1$ //$NON-NLS-2$
buffer.append("</p>"); //$NON-NLS-1$
}
public void setEditor(IEditorPart editor) {
if (editor != null) {
fEditor = editor;
final IWorkbenchPage page = editor.getSite().getPage();
page.addSelectionListener(IDebugUIConstants.ID_DEBUG_VIEW, this);
page.addPartListener(this);
// initialize selection
Runnable r = new Runnable() {
public void run() {
fSelection = page
.getSelection(IDebugUIConstants.ID_DEBUG_VIEW);
}
};
CDebugUIPlugin.getStandardDisplay().asyncExec(r);
}
}
public void selectionChanged(IWorkbenchPart part, ISelection selection) {
fSelection = selection;
}
public void partActivated(IWorkbenchPart part) {
}
public void partBroughtToTop(IWorkbenchPart part) {
}
public void partClosed(IWorkbenchPart part) {
if (part.equals(fEditor)) {
IWorkbenchPage page = fEditor.getSite().getPage();
page.removeSelectionListener(IDebugUIConstants.ID_DEBUG_VIEW, this);
page.removePartListener(this);
fSelection = null;
fEditor = null;
}
}
public void partDeactivated(IWorkbenchPart part) {
}
public void partOpened(IWorkbenchPart part) {
}
public IInformationControlCreator getHoverControlCreator() {
return null;
}
protected ISelection getSelection() {
return fSelection;
}
protected IAdaptable getSelectionAdaptable() {
if (fSelection instanceof IStructuredSelection) {
IStructuredSelection selection = (IStructuredSelection) fSelection;
if (selection.size() == 1) {
Object element = selection.getFirstElement();
if (element instanceof IAdaptable) {
return (IAdaptable) element;
}
}
}
return null;
}
protected IEditorPart getEditor() {
return fEditor;
}
/**
* Replace any characters in the given String that would confuse an HTML parser with their escape sequences.
*/
private static String makeHTMLSafe(String string) {
StringBuffer buffer = new StringBuffer(string.length());
for (int i = 0; i != string.length(); i++) {
char ch = string.charAt(i);
switch (ch) {
case '&':
buffer.append("&"); //$NON-NLS-1$
break;
case '<':
buffer.append("<"); //$NON-NLS-1$
break;
case '>':
buffer.append(">"); //$NON-NLS-1$
break;
default:
buffer.append(ch);
break;
}
}
return buffer.toString();
}
}